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Biomedical subjects

A Franco

Publications and source records attributed to A Franco.

At least 181 records · Page 10Linked to original sources
PubMed1993

The inhibition of different T cell lines specific for the same antigen with TCR antagonist peptides.

To further understand and evaluate the phenomenon of TCR antagonism, we wished to determine whether analogs of an antigenic determinant could antagonize a specific polyclonal response. To this end, the ability of TCR antagonist peptides to inhibit a panel of five different DR4w4-restricted, influenza hemagglutinin 307-319-specific T cell lines was examined. An analysis of their V beta and J beta usage indicated that each of these five T cell lines expressed different TCR. A series of HA 307-319 single amino acid substituted analogs were used to determine the fine Ag specificities of the different lines. Ag analogs that demonstrated little or no stimulatory capacity were then examined for their ability to act as TCR antagonists by inhibiting the proliferative response of these five lines. Overall, 17 different peptide analogs capable of antagonizing at least one T cell line were identified. Although no single analog was capable of inhibiting all five T cell lines, two different analogs were identified that were capable of inhibiting four of five of the T cell specificities examined.

Amino Acid Sequence↗
PubMed1993

Evaluation of a colour test for rapid detection of Salmonella.

The performance of a colour test (Wellcolex) for rapid detection of the most frequently isolated O serogroups of salmonella (A, B, C, D, E/G) and the Vi antigen was evaluated using colonies grown on enteric differential agar media and in selenite broth. The test had excellent sensitivity (100%) and specificity (100%) with colonies taken directly from primary culture plates. Initial tests in selenite broth showed limited sensitivity (62.1%) but by using high quality media and modifying the inoculation procedure, sensitivity was greatly improved (99%).

Bacteriological Techniques↗
PubMed1993

A new technique for accessing the cerebral ventricles of the horse.

A technique is described for catheterisation of the ventricular recess within the olfactory bulb of the horse. Twelve adult horses were used. The olfactory recess is in the frontal region, 42 +/- 3 mm below the skin, on the line joining the supraorbital foramina, and approximately 18 +/- 2 mm from the midline. The approach is relatively easy under normal experimental conditions.

Animals↗
PubMed1993

Craniofacial angle in dolicho-, meso- and brachycephalic dogs: radiological determination and application.

Observations on craniofacial axes and angles were made on fifty dogs belonging to five breeds, by means of radiological techniques (lateral radiographs) and biostatistical methods. The craniofacial angles were found to be 25-26 degrees (greyhound), 19-20 degrees (pointer), 20-21 degrees (German shepherd), 13-14 degrees (boxer) and 9-10 degrees (Pekinese). Shortening of the head in brachycephalic dogs implies a more perpendicular development of the cranium relative to the facial axis. The possible application of these data in the determination of morphological types in many fields is discussed.

Animals↗
PubMed1993

Histomorphometric analysis of the abomasum of the sheep during development.

Histomorphometric analyses were carried out on 64 embryos and fetuses and on 20 sheep (early postnatal to adult age). Histodifferentiation of the abomasum took place at 33 days of fetal life, with the appearance of abomasal villi at 53 days. By 64 fetal days, the epithelium had changed from pseudostratified to simple mucous cylindrical. Acidic glycoproteins appeared at 46 fetal days. Neutral glycoproteins did not appear until later stages of development, near birth. We believe that the configuration of a simple epithelium with acidic secretion is enhanced at birth by the secretion of neutral glycoproteins which act as a buffer against acidic substances, and particularly against the abomasal acidity during lactation. Growth curves and formulae were set out for each tissue layer.

Abomasum↗
PubMed1993

Gastric uptake of Tc-99m MDP in a child treated with isotretinoin.

The side effects of prolonged isotretinoin therapy include progressive calcification of ligamentous and tendon insertions, premature fusion of epiphyses, and modeling abnormalities of long bones. Increased calcification of gastric mucosa has been reported only in animal studies, but not in humans. A case of a child who was treated with isotretinoin for 26 months for a dermatologic disorder and who showed abnormal gastric uptake of 99m-Tc MDP on a bone scan is reported.

Bone and Bones↗
PubMed1993

[Mathematical models applied to the growth of the ovine stomach during intrauterine life].

One hundred forty four ovine embryos and feti were used in an investigation to determine mathematical models describing the histomorphometric growth of tissues and compartments of the ruminant stomach. The results indicate that during prenatal life the diameter of the gastric chambers increase more slowly than the length. The tissue layers of the gastric walls, particularly the muscular tunic of all compartments demonstrated a uniform tendency toward more rapid development than the compartment walls proper.

Animals↗
PubMed1993

Ontogeny and distribution of gastrin cells in the gastrointestinal tract of the sheep.

Indirect immunofluorescence and peroxidase-antiperoxidase methods were used to analyze the development and distribution of gastrin-producing cells in 24 embryos and fetuses (at 26-120 days of prenatal life) of sheep and in 10 newborn sheep. Plasma gastrin concentrations were measured by radioimmunoassay in blood samples taken for the immunocytochemical study. Gastrin cells first appeared at 69 and 77 days of gestation in the duodenum and pyloric antrum, respectively. Gastrin immunoreactive cells were very numerous in the pyloric region, numerous in the duodenum, scarce in the jejunum and rare in the ileum. None were detected in the cardiac or fundic regions of the abomasum or in the colon or rectum. Plasma gastrin concentrations were first detected at 69 days, increasing gastrin levels being observed during the development stages just before birth. The differences between sheep and other species in the distribution and development of these endocrine cells are discussed.

Animals↗
PubMed1993

Histomorphometric analysis of the omasum of sheep during development.

Histomorphometric and scanning electron microscopic analyses were performed on 74 embryos and fetuses and 20 sheep (early postnatal to adult age). Histologic differentiation of the omasum took place at 33 days of fetal life, with the appearance of first-order laminae. Second-, third-, and fourth-order laminae appeared at 39, 50, and 59 days, respectively. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life, decreasing quantitatively until birth, before subsequently stabilizing in postnatal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Growth curves and formulas were constructed for each tissue layer. Initial tests involved multiplicative (y = axb), exponential (y = EXP [a + bx]), linear (y = a + bx), and polynomial models (y = a + bx + cx2 + dx3).

Animals↗
PubMed1993

[Prostatic adenocarcinoma presenting as retrovesical cystic formation. Report of a case].

Presentation of one case of prostate adenocarcinoma with a peculiar evolution towards a large cystic formation at the expense of the left prostate lobe, clinically revealed as a picture of poor performance status and impaired consciousness secondary to obstructive renal failure. The benign evolution of the case, even though the patient received no specific therapy, is emphasized.

Adenocarcinoma↗
PubMed1993

[Carotid stenoses. Non-invasive exploration].

Doppler flowmeter and ultrasound imaging techniques, currently associated (duplex), have made important contributions to the simple and early non invasive diagnosis of carotid stenosis lesions in the cervical region for more than 20 years. These exploratory methods are reliable when a significant degree of stenosis (greater than about 60%) exists. Moderate degrees of stenoses or plaques are evaluated morphologically, calcifications and ulcerations being enhanced by staining techniques. But the evaluations have not really demonstrated exact correlations between anatomicopathologic and ultrasound images. The intracranial arteries and the circle of Willis are explored indirectly during the cervical examination by cautious compressive maneuvers or directly by trans-cranial Doppler. Whereas angiography competes with ultrasound imaging as a standard examination in the neck region, it nevertheless remains effective for the study of the intracranial arteries. Newer techniques, such as high-field MRI angiography, tridimensional ultrasonography or ultrasound recording of vascular flow rate without Doppler, will doubtlessly transform the diagnosis of symptomatic or asymptomatic carotid stenosis. From the strategic point of view, ultrasound imaging techniques will retain their role of a decisional pivot, since they are simple to use and are of very wide accessibility to competent vascular physicians in the context of an organized care network.

Carotid Stenosis↗
PubMed1993

Normalization of depressed natural killer activity after interferon-alpha therapy is associated with a low frequency of relapse in patients with chronic hepatitis C.

In the present study, we found that human recombinant interferon-alpha (rIFN-alpha) given at a dose of 3 x 10(6) units thrice weekly for three months, and 1.5 x 10(6) units thrice weekly for the next three months, was able to restore depressed natural-killer (NK) activity to normal values in 12 out of 21 chronic hepatitis C patients positive for anti-HCV antibodies. In all of these patients, NK normalization was still sustained after three months from suspension of therapy. Eighteen patients also showed a normalization of the alanine aminotransferase (ALT) level by the end of treatment (responder patients), independently of changes in NK activity. No significant improvement in either NK activity or aminotransferase levels was seen among 20 untreated patients. In 8 responder patients (1 with normalized and 7 with low NK activity), ALT levels returned to pre-therapy values within three months after suspension of rIFN-alpha administration (relapse). We found that patients who normalized NK activity had a lower frequency of relapse as compared to patients with low NK activity by the end of treatment (p > 0.01). Immunofluorescence analysis of biopsy-derived liver tissue revealed that rIFN-alpha was able to induce strong MHC class I antigen expression on hepatocytes of treated patients, but this was not related to the clinical course.

Adult↗
PubMed1993

Histomorphometric analysis of the reticulum of the sheep during development.

Histomorphometric and scanning electron microscopic analysis were performed on 74 embryos and foetuses and on 20 sheep (early post-natal to adult age). Histodifferentiation of the reticulum took place at 33 days of foetal life. Reticular ribs were observed as evaginations of the epithelial stratum germinativum at 64 days. Neutral mucopolysaccharides first appeared in epithelial cells at 46 foetal days, thereafter to decrease gradually in number, subsequently stabilising in postnatal life. Acid mucopolysaccharides, mucins and mucoid compounds were not detected. Growth curves and formulae were constructed for each tissue layer. Initial test involved multiplicative (y = axb), linear (y = a+bx) and polynomial model (y = a+b+cx2+dx3).

Animals↗
PubMed1993

Geographic variation in the prevalence of Raynaud's phenomenon: Charleston, SC, USA, vs Tarentaise, Savoie, France.

We estimated the prevalence of Raynaud's phenomenon (RP) in the general population of 2 geographic areas, Charleston County, South Carolina, USA, and Tarentaise, Savoie, France, using the same methodology in both countries. The first phase of the study, consisting of the telephone survey of a randomly drawn sample of households, yielded 2086 completed interviews in Charleston and 2000 in Tarentaise. Cold sensitivity or unusual digital color changes were reported by 17.9% of the subjects in Charleston and by 31.3% in Tarentaise. In the second phase of the study the diagnosis of RP was made by a medical team. Based on these results, the estimated prevalence of RP is 5.0% (0.8% SE) in Charleston (women 5.7%, men 4.3%) and 16.8% (2.0% SE) in Tarentaise (women 20.1%, men 13.5%).

Adult↗